You are being silly. If there are 50.000 visitors and 1 percent is interested. How do you organize to have a face to face with 500 people on a single day?
Besides, the assumption is that you can reach more people through one person writing an article about your game, which is why they invite press only. That said I don't think that all who visited on press day will actually write an article.

— Computern. A machine which flawlessly performs the instructions it is given, no matter how flawed those instructions may be.